Identification of zinc phosphide in a falsely labeled rodenticide bait

"Kela" is a commercial rodenticide bait commonly used in Israel, made of wheat grains, which, according to its label, contains chlorophacinone. This product was involved in the death case of a man in which the victim's female companion was accused of assisting in this suicide and was subsequently convicted. Analysis of the wheat grains revealed zinc phosphide, whose use is restricted to authorized exterminators only, instead of chlorophacinone. Zinc phosphide was identified using microscopic examination, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and X-ray powder diffraction (XRD).